The Stanford Arthritis Center conducts research programs, educational programs, and patient care activities directed toward methods of improving the health outcomes of patients with rheumatic diseases. The Center implements new community and educational programs and gauges their success by the outcome experienced by patients. The Center draws upon resources provided by a strong research program, a consortium of community physicians, a major data-handling program (ARAMIS), cooperating hospitals and health plans, significant patient education expertise, and the skills of economistas, epidemiologists, educators, and health evaluators in assessing new programs. Central to these projects is the evaluation of health outcome by trained independent assessors. Techniques for assessing functional outcome have been developed for use by trained health professionals. Together with traditional measures, such as death and cost, these techniques allow new programs to be rigorously evaluated, with control populations studied in parallel, and with objective assessment of benefit. Programs of the Center utilize similar designs. New programs are initially offered as part of a defined patient group; other patients are treated by standard techniques. At six-month intervals all patients have independent assessment of arthritis outcome status. Data are analyzed for the effect upon patient outcome. Initial programs include: (1) Patient Education, (2) creation of a Multi-Disciplinary Arthritis Team, (3) evaluation of health outcomes achieved by physicians with different levels of training, (4) study of socio-economic and medical variables and outcome in juvenile arthritis, (5) functional outcome following total joint replacement, and (6) community-wide controlled therapeutic trials. Improvement in patient outcome nationally must take place within the constraints of finite resources. In devoting this Center to the evaluation of patient outcome, we expect to quantify benefits accruing to the patient from specific interventions and to test guidelines for a logical organization of resources for arthritis care.